Improvement in drills



UNITED STATES PATENT OFFICE.

LOOMIS G. MARSHALL, OF MOKENA, ILLINOIS.

IMPROVEMENT IN DRILLS.

Specification forming part of Letters Patent No. 48,819, dated July 18,i865.

To all whom it may concern:

Be it known that I, LooMIs G. MARSHALL, ot Mokena, Will county, State ofIllinois, have invented new and useful Improvements in Ohambering-Drillsfor Widening Oavities in Oil-Wells; and I do hereby declare thefollowing to be an exact description thereof, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,making a part of this specification.

Thenature of my invention consists in drills working on pivots, withtheir cutting-edges on their frontend back faces, and dat inclinebottoms, so as to cut upward and form a chamber when required to openthe ssures of rocks that are frequently beyond the main bore ot' thewell, for the purpose of facilitating and increasing the ow of the oilwhen an oil-ssure cannot otherwise be reached, though within a fewinches of the main opening or bore ofthe well, this invention being animprovement on my pivoted chambering-drill patented in 1863.

Figure 1 representsa side view of the drill; Fig. 2, a front or backview, showing the cutting-edges. Fig. 3 shows a side View of the drillexpanded with its cuttingedges.

A represents the rod with a female screw, into which the drillsstem O,with the mulescrew D and shoulder E, is attached.

G G are the expansion drills attached t0 the stem O by pivots H. Thesedrills have iat incline bottoms, so that the points J J spread and wolkoutward. Their sides or front and back faces have three or more angularcuttingedges, I, each edge being a separate drill to cut upward as thebottom spreads and works outward. These drills may be made solid or inthree pieces, each pie-ce having its own cuttingedge I. The tops ofthese drills G Work on the pivots H in a socket-joint, the tops beingrounding, and the bottom of the stem C being concave for the round topsof the drills to work close, and by the shoulder E to take oft' the jarof the drill from the pivots H. Ay .tapering point, K, projects downwardbetween The obj ect of making these chambers is to openfmore fissures inthe rocks, as the oil-fissuresV` prove to be more vertical thanhorizontal, and sometimes extend but a few inches beyond the main bore.

What I claim as my invention, and desire to secure by Letters Patent,is-` The construction and combination of thepivoteddrills,havingfrontand back cutting-edges and dat incline bottomsfor chambering and cutting outward and upward, as herein deA scribed.

LOOMIS G. MARSHALL.

Witnesses:

J. FRANKLIN BEIGAET, EDM. F. BROWN.

